Grumbacher Academy Watercolor - Raw Sienna, 7.5 ml tube

Pigment Information

This color contains the following pigments:

PBr7-Raw Sienna

PY42-Yellow Iron Oxide

Pigment Name

PBr7-Raw Sienna

Pigment Type

earth

Chemical Name

hydrated iron oxide

Chemical Formula

α-FeO3+(OH) or Fe2O3

Properties

Raw Sienna is a moderately dull deep earth yellow with medium tinting strength and excellent transparency. It is one of the basic permanent artists' pigments and is made from a form of limonite clay whose yellow-brown color results from ferric oxides. Raw Sienna is preferable to Yellow Ochre for creating flesh tones, due to its higher subtlety of color when mixed with white. It creates a bright Ochre when mixed with Cadmium Yellow and creates greens and grays when mixed with Ultramarine. Raw Sienna dries quickly.

Permanence

Raw Sienna has good permanence.

Toxicity

Raw Sienna has no significant hazards.

History

Raw Sienna has been used as a pigment since prehistoric times, although its current name came about during the Renaissance. It comes from the city of Siena, in Italy, and is short for terra di Siena, meaning earth of Siena. Sienna was famous for the mining and production of earth pigments from the Renaissance until World War II. Due to the depletion of clay deposits in Tuscany, Italian siennas now come from other areas, including Sicily and Sardinia.

Pigment Name

PY42-Yellow Iron Oxide

Chemical Name

iron(III)-oxide, hydrated

Chemical Formula

Fe2O3 • H2O

Properties

Yellow Ochre provides artists with earthtones from cream to brown. It has good hiding power, produces a quick drying paint, and can be safely mixed with other pigments. Its transparency varies widely from opaque shades to more transparent ones, which are valued for their use as glazes. If gypsum is present, Yellow Ochre is not suitable for frescoing. (See Brown Ochre, PY43.) PY42 is made from synthetic iron oxides. PY43 is made from natural iron oxide.

Permanence

Yellow Ochre has excellent permanence because ochres are some of the most permanent pigments available.

Toxicity

Yellow Ochre is non-toxic unless it contains manganese.

History

Ochre comes from the Greek word ochros, meaning pale yellow. It was one of the first pigments to be used by human beings, and evidence of its use has been found at 300,000 year old sites in France and the former Czechoslovakia.